Abstract
Surfactin lipopeptide is an eco-friendly microbially synthesized bioproduct that holds considerable potential in therapeutics (antibiofilm) as well as in agriculture (antifungal). In the present study, production of surfactin by a marine strain
Bacillus velezensis
MS20 was carried out, followed by physico-chemical characterization, anti-biofilm activity, plant growth promotion, and quantitative Reverse Transcriptase—Polymerase Chain Reaction (q RT-PCR) studies. From the results, it was inferred that MS20 was found to produce biosurfactant (3,300 mg L
–1
) under optimized conditions. From the physicochemical characterization [Thin layer chromatography (TLC), Fourier Transform Infrared (FTIR) Spectroscopy, Liquid Chromatography/Mass Spectroscopy (LC/MS), and Polymerase Chain Reaction (PCR) amplification] it was revealed to be surfactin. From bio-assay and scanning electron microscope (SEM) images, it was observed that surfactin (MIC 50 μg Ml
–1
) has appreciable bacterial aggregation against clinical pathogens
Pseudomonas aeruginosa
MTCC424,
Escherichia coli
MTCC43,
Klebsiella pneumoniae
MTCC9751, and Methicillin resistant
Staphylococcus aureus
(MRSA) and mycelial condensation property against a fungal phytopathogen
Rhizoctonia solani
. In addition, the q-RTPCR studies revealed 8-fold upregulation (9.34 ± 0.11-fold) of
srf
A-A gene compared to controls. Further, treatment of maize crop (infected with
R. solani
) with surfactin and MS20 led to the production of defense enzymes. In conclusion, concentration and synergy of a carbon source with inorganic/mineral salts can ameliorate surfactin yield and, application wise, it has antibiofilm and antifungal activities. In addition, it induced systemic resistance in maize crop, which makes it a good candidate to be employed in sustainable agricultural practices.